Fractures of the hip represent a serious and growing public health problem; an estimated 200,000 such fractures occur annually with a direct annual cost on the order of $7 billion. Medication use could affect the risk of hip fracture by increasing the risk of falls or by altering bone mass. The objective of this epidemiologic study is to investigate the association of medication use and hip fractures in a large defined population: the 120,000 elderly residents of the province of Saskatchewan who are covered by a universal health insurance program with computerized records. The study will encompass the ten years 1976 through 1985, with an estimated 7,000 incident hip fracture cases. The four specific substudies to be performed include 1) studies of hip fracture incidence in the elderly; 2) studies of the association of psychotropic drug use in the elderly with risk of hip fracture; 3) the association of short-term use of antihypertensive medications and risk of hip fracture; and 4) the association between long-term use of thiazide divretics and reduction of hip fracture risk.